xmickmaniax4
Mechanical
- Apr 18, 2017
- 1
This is from the NCEES 2017 practice problem.
See attached the question and solution and ref material.
I believe the solution is wrong. The values of R for the air gap and the inside film are incorrect.
For the air gap it looks like the direction of heat flow was chosen as upward instead of downward. Because it a summer condition heat is moving from outside in or the roof down. I believe the R value for the air gap to be 3.41
Also for the inside film , .68 is incorrect that is only for vertical walls. Just wanted some confirmation here.
Here's the questions provided solutions an the necessary references in the imgur link.
Imgur link
See attached the question and solution and ref material.
I believe the solution is wrong. The values of R for the air gap and the inside film are incorrect.
For the air gap it looks like the direction of heat flow was chosen as upward instead of downward. Because it a summer condition heat is moving from outside in or the roof down. I believe the R value for the air gap to be 3.41
Also for the inside film , .68 is incorrect that is only for vertical walls. Just wanted some confirmation here.
Here's the questions provided solutions an the necessary references in the imgur link.
Imgur link
